We report the results of a search for the decay B0 → X(3872)(→J/ψπ+π−)γ. The analysis is performed on a data sample corresponding to an integrated luminosity of 711 fb−1 and containing 772×106BB¯ ...pairs, collected with the Belle detector at the KEKB asymmetric-energy e+e− collider running at the ϒ(4S) resonance energy. We find no evidence for a signal and place an upper limit of B(B0 → X(3872)γ) × B(X(3872) → J/ψπ+π−)<5.1 × 10−7 at 90% confidence level.
Production of technical parts for Mechanical Engineering field is very important. There are many conditions which the produced parts have to satisfy. Very important for functional parts are accuracy ...of final parts. This accuracy could be evaluated in different ways. For example it can be evaluated shape accuracy or dimensional accuracy. This paper is focused to Fused Deposition Modelling (FDM) technology which is used for Additive Manufacturing process. The parts in additive manufacturing are produced directly from virtual model and digital file which could be obtained by direct modelling with CAD software of by 3D scanning. Published paper deals realized research where the full factor experiment was prepared and measured shape and dimensional accuracy of produced specimens. There are designed two types of specimens with different shapes and dimensions. Digital models are processed with different different 3D printer settings. Measured values are evaluated by statistical methods.
We report a search for a dark vector gauge boson U′ that couples to quarks in the decay chain D*+→D0π+,D0→KS0η,η→U′γ, U′→π+π−. No signal is found and we set a mass-dependent limit on the baryonic ...fine structure constant of 10−3−10−2 in the U′ mass range of 290 to 520 MeV/c2. This analysis is based on a data sample of 976 fb−1 collected by the Belle experiment at the KEKB asymmetric-energy e+e− collider.
We have developed a new type of particle identification device, called an aerogel ring imaging Cherenkov (ARICH) counter, for the Belle II experiment. It uses silica aerogel tiles as Cherenkov ...radiators. For detection of Cherenkov photons, hybrid avalanche photo-detectors (HAPDs) are used. The designed HAPD has a high sensitivity to single photons under a strong magnetic field. We have confirmed that the HAPD provides high efficiency for single-photon detection even after exposure to neutron and
$\gamma $
-ray radiation that exceeds the levels expected in the 10-year Belle II operation. In order to confirm the basic performance of the ARICH counter system, we carried out a beam test at the using a prototype of the ARICH counter with six HAPD modules. The results are in agreement with our expectations and confirm the suitability of the ARICH counter for the Belle II experiment. Based on the in-beam performance of the device, we expect that the identification efficiency at
$3.5\,{\rm GeV}/c$
is 97.4% and 4.9% for pions and kaons, respectively. This paper summarizes the development of the HAPD for the ARICH and the evaluation of the performance of the prototype ARICH counter built with the final design components.
Likelihood analysis of patterns in a time-of-propagation (TOP) counter Starič, M.; Inami, K.; Križan, P. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2008, Letnik:
595, Številka:
1
Journal Article
Recenzirano
For the upgrade of the Belle spectrometer, a Time-Of-Propagation (TOP) counter is planned in the barrel region. In this contribution, an analytical likelihood function to analyze the time dependent ...patterns on the image plane of the counter is presented.
The branching fractions of the Υ(1S) inclusive decays into final states with a J/ψ or a ψ(2S) are measured with improved precision to be B(Υ(1S)→J/ψ+anything)=(5.25±0.13(stat)±0.25(syst))×10-4 and ...B(Υ(1S)→ψ(2S)+anything)=(1.23±0.17(stat)±0.11(syst))×10-4. The first search for Υ(1S) decays into XYZ states that decay into a J/ψ or a ψ(2S) plus one or two charged tracks yields no significant signals for XYZ states in any of the examined decay modes, and upper limits on their production rates in Υ(1S) inclusive decays are determined.
Here, we present a measurement of angular observables and a test of lepton flavor universality in the B → K*ℓ+ℓ- decay, where ℓ is either e or μ . The analysis is performed on a data sample ...corresponding to an integrated luminosity of 711fb-1 containing 772×106 B B ¯ pairs, collected at the Υ ( 4S ) resonance with the Belle detector at the asymmetric-energy e+e- collider KEKB. The finding is consistent with standard model (SM) expectations, where the largest discrepancy from a SM prediction is observed in the muon modes with a local significance of 2.6σ .
We study B --> K(*)l+l- decays (l = e, mu) based on a data sample of 657 x 10(6) BB pairs collected with the Belle detector at the KEKB e+e- collider. We report the differential branching fraction, ...isospin asymmetry, K* polarization, and the forward-backward asymmetry (A(FB)) as functions of q2 = M(ll)(2)c2. The fitted A(FB) spectrum exceeds the standard model expectation by 2.7 standard deviations. The measured branching fractions are B(B --> K*l+l-) = (10.7(-1.0)(+1.1) +/- 0.9) x 10(-7) and B(B --> Kl+l-) = (4.8(-0.4)(+0.5) +/- 0.3) x 10(-7), where the first errors are statistical and the second are systematic, with the muon to electron ratios R(K*) = 0.83 +/- 0.17 +/- 0.08 and R(K) = 1.03 +/- 0.19 +/- 0.06.
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